Development of a truly effective anti-cocaine medication has been very challenging, particularly for treatment of cocaine overdose. There is still no FDA-approved anti-cocaine medication. Enhancing cocaine metabolism by administration of butyrylcholinesterase (BChE) has been recognized as a promising treatment strategy for cocaine abuse. However, the catalytic activity of this plasma enzyme is low against the naturally occurring (-) - cocaine. Our recent integrated computational-experimental effort has led to discovery of high-activity mutants of human BChE, known as cocaine hydrolases (CocHs), with >1,000-fold improved catalytic efficiency against cocaine compared to wild-type BChE. In vivo evidences indicate that our discovered CocHs are promising candidates for development of an anti-cocaine medication, especially for the overdose treatment. In this proposed project, we focus on the selection and optimization of the most promising CocH as a novel therapeutic candidate for cocaine overdose treatment through a combined use of various in silico, in vitro, and in vivo approaches. The specific aims are: (1) To prepare and characterize the discovered CocHs in vitro for their catalytic activity and stability; (2) To characterize the CocHs in vivo for their potency, biological/circulatory half-lives, and immunogenicity by using the CocH materials prepared in Aim 1; (3) To design, prepare, and characterize new CocH entities that have not only a high in vivo potency, but also a higher thermal stability and a longer circulatory half-life without immunogenicity. Accomplishment of this proposed investigation will result in the identification and development of the most promising CocH entity that has a high in vivo potency in the protective and rescuing effects, a high stability, and a sufficiently long biological half-life without immunogenicity. The CocH entity optimized in this investigation is expected to be highly effective and safe as an exogenous enzyme for cocaine overdose treatment in humans. PUBLIC HEALTH RELEVANCE: Accelerating cocaine metabolism has been recognized as a promising treatment strategy for anti-cocaine medication. Accomplishment of the proposed investigation will result in the identification of reliable candidates of a novel enzyme therapy for cocaine overdose.